1. Field of the Invention
The present invention relates to a composition designed to be a release agent applied to the surface of a molding apparatus and method of using the composition in molding operations. The composition includes a siloxane composition, a cross linking agent, hydrophilic matting particles and a binding agent having hydrophobic and hydrophilic characteristics. The composition is designed to be applied to the surface of a mold, allowing for repeated use without the need for re-applying the composition between uses.
2. Brief Description of Related Technology
Molding processes used to produce molded articles from elastomeric compositions generally use mold release compositions to facilitate removal of formed parts from the mold and to maintain surface quality of the part. Mold release compositions should perform their function without interfering with the formation of the part or the subsequent properties desired from the molded article. Many conventional mold release compositions no longer perform effectively after a single use and therefore require re-application of the release composition for each set of parts. This interrupts the continuity of the molding process, requiring down-time and running the mold without resin to cure the mold release composition.
Mold release compositions are applied to the surface of the molds used to produce elastomeric articles, but commercially available mold release compositions have been shown to perform poorly after a single cycle of use and have been known to leave release composition residue on the surface of the molded part. The transfer of the mold releasing agent to the molded article causes poor finishing such as stickiness of the molded article. Due to this transfer, molded articles are generally required to be cleaned after formation, adding to the time required to complete the article and reducing efficiency.
Moreover, certain articles require different surface finishes. For example, some products require a high glossy, smooth finish. Others, such as automotive parts including dashboards, require a low gloss, matte finish. Providing effective release compositions which form a matte finish has proven especially difficult. Generally, low degree matte finish is currently achieved using sacrificial release agents, which cannot be repeatedly used without reapplication, and further results in release agent transfers.
Thus, a need currently exists for a release agent which allows the formation of an article with a low gloss, matte finish, which has enhanced durability, high cycle capability, and which allows repeated use without re-application of the release agent after each use.